Electric switch



H. KERGEL EI'AL ELECTRIC SWITCH Filed May 27, 1958 Dec. 17, 1940.

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Patented Dec. 17, 1940 UNlTED STATES ELECTRIC SWITCH Hermann Kergel and Johannes Christiansen, I

Radeberg, Germany, assignors to General Electric Company,.a corporation of New York Application May 27,

1938, Serial No. 210,511

In Germany June '1, 1937 Claims.

Our invention relates to improvements in electric switches and more particularly to improvements in disconnecting switches and. especially disconnecting switches of large current-conduct- 5 ing capacity.

An object of our invention is to provide a relatively simple and compact construction of electric switches for conducting, high currents whereby to avoid undesired heating effects particu larly for currents of a frequency higher than usual in power system currents. This and other objects of our invention will appear in more detail hereinafter.

Our invention will be better understood from the following description when considered in connection with the accompanying sheet of drawings, and its scope will be pointed out in the appended claims.

In the accompanying sheet of drawings, Figs. 1-4 illustrate diagrammatically arrangements of different forms of conductors which may be used in carrying out our invention; Fig. 5 represents an end elevation and Figs. 6 a side elevation partially in section of an electric switch embodying our invention; Fig. 7 is a partial side elevation of a modification of the embodiment of our invention shown in Fig. 6; Fig. 8 is an end elevation and Fig. 9 is aside elevation partly in section of another embodiment of our invention; and Fig. 10 is a partial side elevation of a modification of the embodiment of our invention shown in Fig. 9.

High current capacity disconnecting switches have been built with a number of rectangular conducting bars having their flat sides parallel and their edges in. the same plane. With this arrangement of conductors, there is the disadvantage due to skin efiect that the external conductors carry a much greater share of the current than the internal conductors. In other words, the current distribution which it is attempted to achieve by subdivision of the current-conducting path into individual conductors is not obtained in a manner to satisfactorily meet all requirements.

In accordance with our invention, this disadvantage of non-uniform distribution of the current, particularly in high current capacity disconnecting switches having current conducting paths subdivided into a number of individual conductors, is eliminated in that we arrange to have, at least when the switch is closed, the parallel-conducting paths in a hollow cylindrical form, the cross section of which may be elliptical, circular, or suitable arcuate form. In this way,

we provide a switch construction which requires comparatively little space. Moreover, by virtue of the arrangement of the switch blades in such hollow cylindrical form, the common actuating means may be centrally disposed relatively to the switch blades to provide a particularly favorable operating mechanism.

In Figs 1-4, inclusive, we have illustrated cylindrical arrangements of flat bar conductors I, wedge-shaped conductors 2, T-shaped conductors 3, and round bar conductors 4, respectively. In each case, the conductors or switch blades are arranged substantially parallel to each other in a cylindrical form which they are to have at least when the switch is closed although they may also have the cylindrical form when the switch is open. The arrangements shown in Figs. 2 and 3 are preferable from the standpoint of the best current distribution to minimize skin effect since the distance between adjacent conductors i-sgreater towards the center of the cylinder in which the conductors are arranged than ,on'the outside.

The embodiment of our invention shown in Figs. 5 and 6 is illustrated as a thrust type of disconnecting switch wherein by suitably movable means, such as a guide head 5, it is possible to obtain the desired thrust action with operating means centrally attached to the guide head. In this embodiment of our invention the switch blades I are arranged in the form of a hollow. circular cylinder on the guide head 5. By suitable means such, for example, as rollers 5' carried in the guide head 5, this is suitably mounted for longitudinal movement on means such as a guide rod 6 centrally mounted relatively to the blades l. The guide rod 6 is suitably mounted on a stationary support 1 which may be supported by a suitable insulator 8. The member. 1- may also. constitute a terminal to'which the blades l are suitably connected either by flexible leads or by a sliding contact arrangement, as shown. The switch further includes a terminal 9 provided with a plurality of conducting points such as studs [0 which are engaged by the blades I upon movement thereof to the right. This movement may be effected by means such as a crank ll pivoted to the guide head 5 and capable of being actuated by any suitable means, examples of which are well known to the art. The terminal 9 is supported on an insulator 12.

In the modification of our invention shown in Fig. '7, we have illustrated a compressed air operating mechanism which may be remotely controlled. As illustrated, this mechanism comprises a cylinder l3 which, in order to make better use of the available space, may be arranged in the space enclosed by the switch blades I. This cylinder serves to effect the 1ongitudinal movement of the guide head 5. When a compressed air or similar operating mechanism is used, the air conduits l4 may be arranged within the insulator 8 and the support or guide flange I mounted thereon and thence to the cylinder I3, as shown.

In the embodiment of our invention shown in Figs. 8 and 9, the switch blades are pivotally mounted to take the cylindrical form or arrangement when the switch is closed since this is the time when it is actually needed. The blades l are pivoted at spaced points IS on the terminal support 1. With this pivotal arrangement of the switch blades, their simultaneous angular movement may be eifected by the longitudinal movement of an actuating device suitably coupled to the blades. Thus, as shown, in Figs. 8 and 9 the blades I are actuated by suitable means such as a longitudinally movable sleeve l6 through levers l1 pivotally connected to the blades l and the sleeve l6. Depending upon the way in which the blades l are mounted and the way the levers I! are attached, the switch opening movement of the sleeve l6 canbe used to cause the free ends of the blades to be turned either inwardly toward each other, as with the arrangement shown in Fig. 9, or outwardly away from each other, as with the arrangement shown in Fig. 10, by suitable actuating meansillustrated as a lever I8 pivotally mounted as at I9 and pivotally connected to the sleeve Hi. In

both Fig. 9 and Fig. 10 the dotted lines indicate the positions of the blades and the sleevefin the switch open position.

From the illustrated embodiments of our invention, it will be observed that the mount-- ing of the guide head for the movable conductors and of the supporting head of the stationa'ry current-conducting path, with which the movable conductors are brought into contact when the switch is closed, on insulators attached centrally to the guide head and supporting head, respectively, affords a very iavorable possibility for centrally connecting the incoming and outgoing connections .as well as a very favorable distribution of current .forthose parts of the current-conducting paths arranged on the guide head and the supporting head, respectively.

While we have shown and described our invention in considerable detail, we do not desire to be limited to the exact arrangements shown, but seek to cover in the appended claims all those modifications that fall within the true spirit and scope of our invention.

What we claim as new and desire to secure by Letters Patent of the United States, is:

1. An electric switch comprising two stationary insulators, a terminal mounted on one of said insulators and comprising a plurality of interconnected and circularly positioned studs, a corresponding plurality of spaced conducting members for engaging said studs, said conducting members being substantially parallel and in the form of a hollow cylinder of substantially the same diameter as the circle of said studs when in engagement therewith, means for mounting said conducting members on said other insulator for movement to and from said studs including reciprocable means centrally disposed within the hollow cylinder formed by said conducting members, and means for actuating said reciprocable means.

2. An electric switch comprising a terminal having a plurality of interconnected contact points, a plurality of pivotally mounted spaced conductors for engaging said contact points said conductors being substantially parallel and in the form of a hollow cylinder when in engagement with said terminaLand reciprocable means movable in one direction to effect such engagement. 1

3. An electric switch comprising a .support, a plurality of blade members pivotally mounted on said support at spaced points in a circular path for simultaneous movement of their free ends toward a common center, a plurality of interconnected conducting studs one for each of said members spaced from the end of the member and arranged in a corresponding circular path and engageable by themember, and means for efi'ecting the simultaneous engagement of said members and their corresponding studs.

4. An electric switch comprising. a support, a plurality of blade members pivotally mounted on said support at spaced points in an arcuate path, a single terminal member comprising means engageable substantially. simultaneously by all of said blade members, and reciprocable means for eifecting such engagement.

5. An electric switch for, alternating currents comprising a terminal provided with a. plurality of interconnected and circularly positioned studs, a corresponding plurality of parallel conducting members spaced throughout their length and arranged in the form of a hollow cylinder of substantially the same diameter asthelcircle of said studs when in engagement therewith, said conducting members being shaped, spaced and arranged to minimize skin effect, means for mounting said conducting members for 'movement to and from said studs including reciprocable means centrally disposed within the hollow cylinder formed by said conducting members, and means for actuating said reciprocable means. I HERMANN KERGEL.

JOI-IANNES CHRISTIANSEN. 

